I hope to acquire two young Flemish rabbit does shortly. Obviously, this is a giant breed, and much bigger and heavier than most other rabbits. Are they short-lived though, in comparison?

No, the rules that apply to giant breeds of dog, such as the great Dane, indicating that they will have a significantly shorter lifespan, certainly in percentage terms when compared with toy breeds, do not apply as far as these rabbits are concerned.

There does seem to be some evidence, however, that certain bloodlines of these particular rabbits are longer-lived on average than others. It might therefore be worth asking the breeder where you plan to obtain your does about the typical lifespan of his or her rabbits.

When it comes to expenditure, be prepared for proportionately larger feed bills, because British giants generally have very healthy appetites, and they will eat more than their smaller relatives. They must obviously have plenty of space too, and lots of exercise to prevent them from becoming overweight. Obesity is otherwise likely to shorten their lifespan.